EP2196017B1 - Verfahren, vorrichtung und computerprogramm für adaptiven schwarzpunktausgleich - Google Patents

Verfahren, vorrichtung und computerprogramm für adaptiven schwarzpunktausgleich Download PDF

Info

Publication number
EP2196017B1
EP2196017B1 EP08804793.1A EP08804793A EP2196017B1 EP 2196017 B1 EP2196017 B1 EP 2196017B1 EP 08804793 A EP08804793 A EP 08804793A EP 2196017 B1 EP2196017 B1 EP 2196017B1
Authority
EP
European Patent Office
Prior art keywords
black point
image
threshold
pixels
point compensation
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Not-in-force
Application number
EP08804793.1A
Other languages
English (en)
French (fr)
Other versions
EP2196017A1 (de
Inventor
Nicolas P.M.F. Bonnier
Jérôme O.R. GUERMONT
Francis J.M. Schmitt
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Canon Production Printing Netherlands BV
Original Assignee
Oce Technologies BV
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Oce Technologies BV filed Critical Oce Technologies BV
Priority to EP08804793.1A priority Critical patent/EP2196017B1/de
Publication of EP2196017A1 publication Critical patent/EP2196017A1/de
Application granted granted Critical
Publication of EP2196017B1 publication Critical patent/EP2196017B1/de
Not-in-force legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
    • H04N1/46—Colour picture communication systems
    • H04N1/56—Processing of colour picture signals
    • H04N1/60—Colour correction or control
    • H04N1/6058—Reduction of colour to a range of reproducible colours, e.g. to ink- reproducible colour gamut

Definitions

  • the invention relates to a method for mapping an original image from a source gamut colour subspace to a destination gamut colour subspace belonging to a certain output device and having a certain black point, the method comprising a step of black point compensation.
  • the invention also relates to a system for mapping an original image from a source gamut colour subspace to a destination gamut colour subspace belonging to a certain output device and having a certain black point comprising a filter for decomposing the original image in several bands, yielding at least a low pass image and a high pass image; and a a black point compensation component.
  • the invention furhter relates to a computer program for performing the method and a computer readable medium for carrying the program.
  • Gamut mapping algorithms consider an input device's color gamut and an output device's color gamut. Some gamut mapping algorithm are said to be adaptive when they also consider some of the image characteristics such as the image type, histogram, contrast or gamut. Recent techniques consider the image layout and the spatial features. They keep track of the spatial features and try to preserve them in the rendering process.
  • the color conversion algorithm consults the ICC profiles of the two devices (the source device and destination device) and the user's rendering intent (or intent) in order to perform the conversion. Although ICC profiles specify how to convert the lightest level of white from the source device to the destination device, the profiles do not specify how black should be converted.
  • Black Point Compensation also referred to as linear XYZ scaling maps the source's black point to the destination's black point in the CIEXYZ color space, hence scaling intermediate color values.
  • LCA Lightness Compression Algorithm
  • XYZ scaling is considered as a baseline color re-rendering for reasonably similar output-referred source and destination media.
  • Most point-wise ICC workflow implementations apply linear CIEXYZ scaling (e.g. Adobe).
  • Lightness scaling is also proposed in existing spatial gamut mapping algorithms, e.g. a linear compression to the low spatial-frequency band in the log domain, or also an optional sigmoidal lowest spatial-frequency band. Similar techniques have also been used to render High Dynamic Range (HDR) images, where the range of the base layer is compressed using a scale factor in the log domain of the rgb pixel values.
  • HDR High Dynamic Range
  • the method according to the preamble is characterised in that the step of black point compensation is adaptive by in dependence of a histogram of the image, carrying out black point compensation if a number of pixels below the black point of the output device in the histogram is more than a first threshold and carrying out no black point compensation if the number of pixels is less than or equal to the first threshold.
  • BPC will be applied to an image, on an image base, only, if large parts of the image are significantly below the level of the output black point of the device.
  • the histogram might be direction dependent and it might also be a local histogram.
  • the method is further improved in that carrying out black point compensation if the number of pixels below the black point of the output device is more than a first threshold comprises carrying out partial black point compensation if the number of pixels below the black point of the output device is between the first and a second threshold and carrying out full black point compensation if the number of pixels below the black point is more than the second threshold.
  • the method further comprises the step of decomposing the image in images in several bands, resulting in at least a low pass image, where the step of black point compensation is carried out on the low pass image resulting in a black point compensated low pass image; and a step of gamut mapping applied on the black point compensated low pass image.
  • image refers to a set of pixels having values, where each value of a pixel has a value from a colour subspace.
  • Step S2 and S3 together indicated as S4 and corresponding with modules 104 and 106, together indicated as 108, effectively decompose the image in several bands.
  • the image is decomposed in two bands, one containing the local means, the other the local variations.
  • step S7 corresponding with module 113, a spatial and colour adaptive gamut mapping algorithm is applied, further indicated as f(). Due to the bilateral filtering carried out in step S2, the neighbourhood of each pixel is taken into account in such a way that the colour values of the pixels and their relations between neighbours are preserved. This yields I out (114).
  • step S8 corresponding with module 115, I out is converted to the CMYK encoding of the output printer using the relative colourimetric intent of its associated ICC profile. This yields I dest (116).
  • the decomposition is obtained by an edge preserving filter using 5D Bilateral Filtering (BF).
  • BF 5D Bilateral Filtering
  • the size of the filter is a crucial parameter and it will be discussed shortly.
  • the number of frequency bands in the decomposition under consideration is 2, but may be more and a maximum will only be constrained by the cost of the computation time.
  • L BF BF(L)
  • a BF BF ( a )
  • L BF * i ⁇ j ⁇ I in w BF j
  • w BF j d x i x j r p i p j ⁇ j ⁇ I in d x i x j r p i p j
  • I in is the original image
  • d(x i , x j ) measures the geometric closeness between the locations x i of pixel i and x j of a nearby pixel j.
  • r(p i , p j ) measures the colorimetric similarity between the colors (L i , a i , b i ) and (L j , a j , b j ) of pixels i and j.
  • the original CIELAB image is converted to the polar representation CIELCH, i.e. lightness, chroma and hue.
  • CIELCH polar representation
  • the two channels L in and C in of the original image I in are filterred using 5D bilateral filtering. This is illustrated in Fig. 3 .
  • the h in channel is not filtered, to keep the hue unaltered by the proposed SGMA. Nevertheless, since the 5D bilateral filter involves ⁇ E ab distance, the hue will be well taken into account in the filtering of L in and c in channels.
  • the width of the gaussian filter determines the boundary between the lower frequency content going to the low-pass band (considered as local means) and the higher frequency content going to the high-pass band (local details). Setting the appropriate value for ⁇ d is not a trivial task.
  • This choice relates to the definition of 'local details' (i.e. small or minor elements in a particular area). This definition depends on multiple parameters such as the size and resolution of the reproduction, the modulation transfer function of the reproduction device, the viewing conditions, the distance of visualization and the behavior of the human visual system. It is known in the art to model the human visual system by multi-scale decompositions with more than two bands (usually up to five).
  • the ⁇ E ab color distance between the central pixel and nearby pixels is also taken into account. This allows us to avoid halos and to handle specifically the local transitions between local similar pixels. Nearby pixels at small ⁇ E ab distance (i.e.perceived as similar) are filtered. Pixels are less and less filtered as the ⁇ E ab distance be-comes large compared to ⁇ r . Thus ⁇ r determines a reference to set apart small ⁇ E ab from large ⁇ E ab . While small ⁇ E ab values are well correlated with perceived color differences, it is more difficult to define a threshold ⁇ r above which ⁇ E ab values can be considered as large.
  • SCAGMAs One goal of the SCAGMAs is to preserve color differences that would otherwise be mapped by gamut mapping algorithms to the same color of the destination gamut.
  • ⁇ r the average distance between the input and destination gamuts might be considered.
  • the ability of the output device to maintain small differences between colors could also be taken into account.
  • a larger value of ⁇ d means a broader filter in the image domain, thus a larger set of frequencies being filtered. Indeed considering a column of images with increasing ⁇ d going from top to bottom, when browsing the images from top to bottom, one observes that I low becomes blurrier and I high presents more and more details.
  • a larger value of ⁇ r means a larger filter in the color domain, thus a larger range of color transitions being filtered.
  • ⁇ r is very large, the bilateral filter is not modulated by the color content of the filtered area and the resulting blurring of the image becomes similar to the blurring of a two dimensional gaussian filter. It also leads to the introduction of halos near the strong edges. Viewing a row of images with an increasing ⁇ r , one finds more and more color content in I high .
  • these parameters may be set by a user via a user interface, or by a control program based on status and settings of the job and the system.
  • step S5 The step of applying Function g() to the low pass band (step S5, excuted by module 109) will now be further elaborated.
  • Function g() acts on the local means of the input image I in contained in I low . Its goal is to map the gamut of I low into the destination gamut Gamut Destination , while preserving as much as possible the color attributes such as hue, lightness and chroma. It also needs to preserve global rendering.
  • BPC Black Point Compensation
  • Black Point Compensation also referred to as linear XYZ scaling maps the source's black point to the destination's black point in the CIEXYZ color space, hence scaling intermediate color values. It is noted that Black Point Compensation can be considered as a gamut compression algorithm. As such, it produces images that are less saturated. This desaturation is not always welcomed and/or necessary. The method proposed overcomes this disadvantage. The method for BPC will be explained now with reference to Fig. 5.
  • Figure 5 is an elaboration of step S5 in Fig.2 .
  • a histogram of I low is made up.
  • step S55 the total number of pixels, #, with a Y value below Y minDest is determined. Is this number above a first threshold Th1 (step S53, Y), in the next step S54 it is checked if this number is also above a second threshold Th2, where Th2 > Th1. If so (step 54, Y) full black point compensation will be carried out (step S55).
  • Y lowBPC i Y low i ⁇ Y min low 1 ⁇ Y min low 1 ⁇ Y min Dest + Y min Dest
  • Y i lowBPC is the scaled Y value of the destination pixel i
  • Y i low the Y value of the source pixel i
  • Y minlow the minimum Y value of the image
  • Y minDest the minimum Y value of the destination device.
  • Thresholds Th1 and Th2 are parameters that can be set by an operator via a user interface on an apparatus.
  • step S58 the low pass band obtained is further processed.
  • the second step of function g() is the gamut mapping of the low-pass band.
  • the goal of this mapping is to preserve as much as possible the color of each pixel in I low . Preserving the color distance between neighbors is not as critical as when mapping the whole I in , since most of the important details of the decomposed image have been filtered by the 5D bilateral filter and lie in I high .
  • step S6 of Fig.2 executed by module 111 of Fig.1 .
  • step S6 of Fig.2 executed by module 111 of Fig.1 .
  • the local energy within I lowM may substantially be reduced compared to the local energy within I low .
  • SCACLIP is further optimized by changing the mathematical expression of the energy to preserve.
  • the proposed variant has as advantage that the local differences between the original image and the resulting image are better minimized.
  • the proposed Content Adapted Mapping algorithm is related to the gamut expansion topic.
  • the gamut expansion algorithms perform the enhancement on source gamuts that are smaller than the destination gamut.
  • the Adapted Mapping considers wide gamut images such as satellite images with legends. Indeed, legends in satellite images contain saturated colors, which lead to a wider gamut than the printer gamut. For these particular images, we perform a gamut expansion algorithm that doesn't change the chroma of the pixels that are out of the printer gamut, and that perform the expansion of the pixels within the gamut of the printer.
  • Each chroma C 0 of the source image is mapped to the chroma C 1 by using a non linear mapping function.
  • C 1 f C N ⁇ C 0 n for 0 ⁇ C N ⁇ 1.
  • the proposed adapted mapping can be applied to satellite images with labels and globally unsaturated images that contain just few saturated colors which induce wider gamuts than the printer gamut.
  • Fig. 8 shows a diagrammatic representation of the most important parts of a digital printer in which the invention as described above is applied.
  • This apparatus is provided with a user interface 65 and an input unit 66 for receiving digital images made elsewhere, e.g. via a network 67, so that the apparatus is used as a printer.
  • the processing unit 63 is connected to the operating unit 65, being a user interface.
  • the operator interface 65 is provided with setting means for manually setting parameters of the gamut mapping function, for example by means of a slide or button.
  • the user can, for example, indicate by means of the printer driver at his workstation that a colour image must be transformed according to his preferences and then printed taking into account desired values for the parameters.
  • a processing device in the printer transforms the digital colour image to a digital colour image mapped on the destination gamut according to the invention, and prints the transformed image.
  • an ink jet printer comprises a platen 40 driven for rotation in the direction of an arrow A for transporting a paper sheet 42 which serves as an image recording medium.
  • a printhead 44 is mounted on a carriage 46 which is guided on guide rails 48 and travels back and forth in the direction of an arrow B along the platen 40 so as to scan the paper sheet 42.
  • the printhead 44 comprises four nozzle heads 50, one for each of the basic colours yellow, magenta, cyan and black.
  • An ink is supplied to a nozzle head 50 from an ink container (not shown) through a pipe.
  • each nozzle head 50 On the side facing the sheet 42, each nozzle head 50 has a linear array of nozzles 52.
  • the nozzle heads 50 are energised in accordance with image information of an image to be printed on the sheet 42. Signals are transmitted to the printhead 44 through a connector (not shown) mounted on the carriage 46. Signals in accordance with print data arise from a control unit connected to the printhead 44 through a connector (not shown).
  • Each nozzle 52 can be energised separately so as to eject an ink droplet which will form a dot at a corresponding pixel position on the sheet 42.
  • each nozzle 52 can be energised to draw a single pixel line of the intended image.

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Facsimile Image Signal Circuits (AREA)
  • Image Processing (AREA)
  • Color Image Communication Systems (AREA)

Claims (9)

  1. Verfahren zum Abbilden von Farben von Pixeln eines Bildes von einem Quellfarbenbereich auf einen Zielfarbenbereich, der einer Ausgabeeinrichtung zugeordnet ist, wobei beide Bereiche einen Schwarzpunkt haben, welches Verfahren einen Schritt für einen adaptiven Schwarzpunktausgleich aufweist, dadurch gekennzeichnet, dass der Schritt des Schwarzpunktausgleiches in Abhängigkeit von einem Histogramm des Bildes ausgeführt wird, wenn eine Anzahl von Pixeln unterhalb des Schwarzpunktes des Zielfarbenbereichs in dem Histogramm größer ist als ein erster Schwellenwert, und nicht ausgeführt wird, wenn die Anzahl von Pixeln kleiner oder gleich diesem ersten Schwellenwert ist.
  2. Verfahren nach Anspruch 1, bei dem der Schritt der Ausführung des Schwarzpunktausgleiches, wenn die Anzahl von Pixeln unterhalb des Schwarzpunktes des Zielfarbenbereiches größer ist als ein erster Schwellenwert, einen Schritt der Ausführung eines partiellen Schwarzpunktausgleiches einschließt, der eine Linearkombination zwischen keinem Schwarzpunktausgleich und vollem Schwarzpunktausgleich ist, wenn die Anzahl von Pixeln unterhalb des Schwarzpunktes des Zielfarbenbereiches zwischen dem genannten ersten und einem zweiten Schwellenwert liegt, und die Ausführung eines vollen Schwarzpunktausgleiches einschließt, wenn die Anzahl von Pixeln unterhalb des Schwellenwertes größer ist als der genannte zweite Schwellenwert.
  3. Verfahren nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass das Verfahren weiterhin einen Schritt der Zerlegung des Bildes in Bilder in mehreren Frequenzbändern einschließt, was zu wenigstens einem Tiefpassbild führt, wobei der Schritt des Schwarzpunktausgleiches an dem Tiefpassbild ausgeführt wird, was zu einem schwarzpunktkompensierten Tiefpassbild führt, und dass ein Schritt der Abbildung des Bereichs an den Farben des schwarzpunktkompensierten Tiefpassbildes ausgeführt wird.
  4. System zum Abbilden von Farben von Pixeln eines Bildes von einem Quellfarbenbereich auf einen Zielfarbenbereich, der einer Ausgabeeinrichtung zugeordnet ist, wobei beide Bereiche einen Schwarzpunkt haben, welches System aufweist:
    einen Filter zum Zerlegen des ursprünglichen Bildes in mehrere Frequenzbänder, was wenigstens ein Tiefpassbild und ein Hochpassbild ergibt;
    eine Komponente zum adaptiven Schwarzpunktausgleich,
    dadurch gekennzeichnet, dass die Komponente zum adaptiven Schwarzpunktausgleich das Tiefpassbild als ein Eingangsbild nimmt und ein schwarzpunktkompensiertes Tiefpassbild als Ausgangsbild ausgibt, durch Ausführung des Schwarzpunktausgleiches, wenn ein Wert eines Merkmals des Bildes größer ist als ein erster Schwellenwert, und Ausführung keines Schwarzpunktausgleiches, wenn der Wert des Merkmals kleiner oder gleich dem genannten ersten Schwellenwert ist, wobei das Merkmal des Originalbildes ein Histogramm des Bildes ist, das Bild Pixel hat, und der Wert des Merkmals die Anzahl von Pixeln unterhalb des Schwarzpunktes des Zielfarbenbereichs ist, und wobei die Komponente zum Schwarzpunktausgleich durch einen ersten Schwellenwert und einen zweiten Schwellenwert gesteuert wird, wobei die Komponente zum Schwarzpunktausgleich einen Schwarzpunktausgleich ausführt, wenn die Anzahl von Pixeln unterhalb der Schwarzpunktes des Zielfarbenbereiches größer ist als der erste Schwellenwert, mit einem Schritt der Ausführung eines partiellen Schwarzpunktausgleiches, wenn die Anzahl von Pixeln unterhalb des Schwarzpunktes des Zielfarbenbereiches zwischen dem genannten ersten und dem genannten zweiten Schwellenwert liegt, und Ausführung des vollen Schwarzpunktausgleiches, wenn die Anzahl von Pixeln unterhalb des Schwarzpunktes größer ist als der genannte zweite Schwellenwert; und
    eine Komponente zum adaptiven Vereinigen und Abbilden, zum Vereinigen und Abbilden des schwarzpunktkompensierten Tiefpassbildes und des Hochpassbildes, was zu einem Ausgangsbild führt;
    wobei das System weiterhin eine Benutzerschnittstelle zum Einstellen der ersten und zweiten Schwellenwerte aufweist.
  5. System nach Anspruch 4, mit einer Ausgabeeinrichtung zur Ausgabe des Ausgangsbildes.
  6. System nach Anspruch 5, bei dem die Ausgabeeinrichtung ein Tintenstrahldrukkersystem ist.
  7. System nach Anspruch 5, bei dem die Ausgabeeinrichtung ein Anzeigesystem ist.
  8. Computerprogramm zur Veranlassung einer Vorrichtung, das Verfahren zum Abbilden von Farben von Pixeln eines Bildes von einem Quellfarbenbereich auf einen Zielfarbenbereich nach einem der Ansprüche 1 bis 3 auszuführen.
  9. Computerlesbares Medium mit einem Computerprogramm nach Anspruch 8.
EP08804793.1A 2007-09-28 2008-09-26 Verfahren, vorrichtung und computerprogramm für adaptiven schwarzpunktausgleich Not-in-force EP2196017B1 (de)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP08804793.1A EP2196017B1 (de) 2007-09-28 2008-09-26 Verfahren, vorrichtung und computerprogramm für adaptiven schwarzpunktausgleich

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
EP07117464 2007-09-28
EP08305538 2008-09-09
EP08804793.1A EP2196017B1 (de) 2007-09-28 2008-09-26 Verfahren, vorrichtung und computerprogramm für adaptiven schwarzpunktausgleich
PCT/EP2008/062915 WO2009040416A1 (en) 2007-09-28 2008-09-26 Method, apparatus and computer program for adaptive black point compensation

Publications (2)

Publication Number Publication Date
EP2196017A1 EP2196017A1 (de) 2010-06-16
EP2196017B1 true EP2196017B1 (de) 2016-06-08

Family

ID=40032592

Family Applications (2)

Application Number Title Priority Date Filing Date
EP08804793.1A Not-in-force EP2196017B1 (de) 2007-09-28 2008-09-26 Verfahren, vorrichtung und computerprogramm für adaptiven schwarzpunktausgleich
EP08804788A Withdrawn EP2206333A1 (de) 2007-09-28 2008-09-26 Verfahren, vorrichtung und computerprogramm zum transformieren von digitalen farbbildern

Family Applications After (1)

Application Number Title Priority Date Filing Date
EP08804788A Withdrawn EP2206333A1 (de) 2007-09-28 2008-09-26 Verfahren, vorrichtung und computerprogramm zum transformieren von digitalen farbbildern

Country Status (4)

Country Link
US (2) US9467598B2 (de)
EP (2) EP2196017B1 (de)
JP (2) JP5539208B2 (de)
WO (2) WO2009040416A1 (de)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008306377A (ja) * 2007-06-06 2008-12-18 Fuji Xerox Co Ltd 色調整装置および色調整プログラム
US8605083B2 (en) 2009-03-06 2013-12-10 Koninklijke Philips N.V. Method for converting input image data into output image data, image conversion unit for converting input image data into output image data, image processing apparatus, display device
EP2647191A1 (de) 2010-11-30 2013-10-09 OCE-Technologies B.V. Verfahren zur darstellung eines farbbildes mit räumlicher skalenabbildung
JP6005292B2 (ja) * 2012-09-24 2016-10-12 インテル・コーポレーション ビデオ符号化及び復号のためのヒストグラム分割ベースのローカル適応フィルタ
US9014472B2 (en) * 2013-03-15 2015-04-21 Xerox Corporation Color balanced compression in dynamic range mismatched color systems
US9961238B2 (en) 2015-06-07 2018-05-01 Apple Inc. Color gamut size metric estimation
EP3193493A1 (de) * 2016-01-15 2017-07-19 Thomson Licensing Helligkeitsabbildung in zwei stufen
US11908109B1 (en) * 2019-11-04 2024-02-20 madVR Holdings LLC Enhanced video processor
US11615763B2 (en) * 2020-11-05 2023-03-28 Samsung Electronics Co., Ltd. Color gamut compression and extension

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5608548A (en) * 1994-12-23 1997-03-04 Hewlett-Packard Company Automatic color adjustment in a document processing environment

Family Cites Families (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3629409C2 (de) * 1986-08-29 1994-02-17 Agfa Gevaert Ag Verfahren und Vorrichtung zur Kontrastbewertung bei der elektronischen Bildverarbeitung
US5450216A (en) * 1994-08-12 1995-09-12 International Business Machines Corporation Color image gamut-mapping system with chroma enhancement at human-insensitive spatial frequencies
US5848183A (en) * 1996-11-21 1998-12-08 Xerox Corporation System and method for generating and utilizing histogram data from a scanned image
US6954287B1 (en) * 1999-11-05 2005-10-11 Xerox Corporation Gamut mapping preserving local luminance differences with adaptive spatial filtering
US6618171B1 (en) * 2000-02-25 2003-09-09 Xerox Corporation Black point adjustment based on image background
JP3719911B2 (ja) * 2000-05-31 2005-11-24 松下電器産業株式会社 色変換方法および色変換装置
EP1292113A3 (de) * 2001-08-23 2005-03-23 Eastman Kodak Company Einstellung der Grauskala
GB0120489D0 (en) * 2001-08-23 2001-10-17 Eastman Kodak Co Tone scale adjustment of digital images
FI116327B (fi) * 2003-09-24 2005-10-31 Nokia Corp Menetelmä ja järjestelmä väritasapainon automaattiseksi säätämiseksi digitaalisessa kuvankäsittelyketjussa, vastaava laitteisto ja ohjelmalliset välineet menetelmän toteuttamiseksi
US7652808B2 (en) * 2003-12-11 2010-01-26 Xerox Corporation Spatially varying luminance compression gamut mapping system and method
US7421143B2 (en) * 2004-06-01 2008-09-02 Xerox Corporation Systems and methods for optimal dynamic range adjustment of scanned images
US8120570B2 (en) * 2004-12-02 2012-02-21 Sharp Laboratories Of America, Inc. Systems and methods for tone curve generation, selection and application
US7570829B2 (en) * 2005-02-17 2009-08-04 Eastman Kodak Company Selection of alternative image processing operations to maintain high image quality
JP2006303984A (ja) * 2005-04-21 2006-11-02 Fuji Photo Film Co Ltd 色変換定義作成装置、色変換定義作成プログラム、色変換定義作成プログラム記憶媒体、および、色変換定義作成方法
US7554705B2 (en) * 2006-02-15 2009-06-30 Eastman Kodak Company Color gamut mapping with black point compensation
KR20070091853A (ko) * 2006-03-07 2007-09-12 삼성전자주식회사 영상 적응적인 색 재현 장치 및 방법
US8050496B2 (en) * 2007-01-09 2011-11-01 Sharp Laboratories Of America, Inc. Color gamut mapping/enhancement technique using skin color detection
US7933445B2 (en) * 2007-01-09 2011-04-26 Sharp Laboratories Of America, Inc. Color gamut mapping/enhancement technique using skin color detection
EP2206334A2 (de) * 2007-09-28 2010-07-14 OCE-Technologies B.V. Verfahren, vorrichtung und computerprogramm zur adaptiven kompensation eines mtf
US8265387B2 (en) * 2009-04-24 2012-09-11 Xerox Corporation Adaptive spatial gamut mapping via dynamic thresholding

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5608548A (en) * 1994-12-23 1997-03-04 Hewlett-Packard Company Automatic color adjustment in a document processing environment

Also Published As

Publication number Publication date
WO2009040416A1 (en) 2009-04-02
US8373898B2 (en) 2013-02-12
JP5539208B2 (ja) 2014-07-02
US9467598B2 (en) 2016-10-11
WO2009040414A1 (en) 2009-04-02
US20100253954A1 (en) 2010-10-07
US20100272353A1 (en) 2010-10-28
JP2010541355A (ja) 2010-12-24
EP2196017A1 (de) 2010-06-16
JP2010541356A (ja) 2010-12-24
EP2206333A1 (de) 2010-07-14

Similar Documents

Publication Publication Date Title
US9467598B2 (en) Method, apparatus and computer program for adaptive black point compensation
US8390887B2 (en) Method, apparatus and computer program for adaptive compensation of a MTF
US8830530B2 (en) Image processor and image processing method generating first and second multi-value density data or performing quantization based on an image characteristic
EP2396963B1 (de) Bildverarbeitungssystem zur verarbeitung eines digitalen bilds und bildverarbeitungsverfahren zur verarbeitung eines digitalen bilds
US8553279B2 (en) Image forming apparatus and a control method to improve image quality based on an edge pixel
JP5333389B2 (ja) 画像処理装置及び画像処理プログラム
US8149465B2 (en) Coloring image generating apparatus and coloring image generating method for generating a coloring image from an image using an edge intensity frequency distribution of the image
US20110298857A1 (en) Image Processing Apparatus And Program
US11416723B2 (en) Image processing apparatus, and non-transitory computer-readable recording medium therefor
US20150373228A1 (en) Signal conversion method and apparatus, program, and print system
JP4788393B2 (ja) 画像処理装置、画像処理方法および画像処理プログラム
US8665498B2 (en) Method and system for automatically detecting and processing halftone regions in scanned documents
US20110128561A1 (en) Image processing apparatus and image processing method
US20110019238A1 (en) Reducing ink bleed artifacts for rgb images
JP5887715B2 (ja) 画像処理装置および画像処理方法
JP4788394B2 (ja) 画像処理装置、画像処理方法および画像処理プログラム
US7916349B2 (en) Color pixel error diffusion in a CMYK input color space
US8488198B2 (en) Image processing apparatus and image processing method
Bonnier et al. Improvements in spatial and color adaptive gamut mapping algorithms
JP2003309732A (ja) 画像処理装置、画像形成装置、画像処理方法、コンピュータプログラム及び記録媒体
JP2023056117A (ja) 画像処理装置
JP2004299171A (ja) 有彩１次色インクと有彩２次色インクとを含む複数のインク成分への分版処理
JPH114356A (ja) カラー変換方法
JP2018142781A (ja) 画像処理装置、画像処理システム、画像処理方法およびそのコンピュータープログラム
EP1757082A1 (de) Arbeitsablaufverfahren für digitalen druck und bildverarbeitung

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20100428

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MT NL NO PL PT RO SE SI SK TR

AX Request for extension of the european patent

Extension state: AL BA MK RS

DAX Request for extension of the european patent (deleted)
17Q First examination report despatched

Effective date: 20120803

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

INTG Intention to grant announced

Effective date: 20160107

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MT NL NO PL PT RO SE SI SK TR

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: DE

Ref legal event code: R096

Ref document number: 602008044641

Country of ref document: DE

REG Reference to a national code

Ref country code: AT

Ref legal event code: REF

Ref document number: 805930

Country of ref document: AT

Kind code of ref document: T

Effective date: 20160715

REG Reference to a national code

Ref country code: NL

Ref legal event code: FP

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 9

REG Reference to a national code

Ref country code: LT

Ref legal event code: MG4D

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20160608

Ref country code: FI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20160608

Ref country code: NO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20160908

REG Reference to a national code

Ref country code: AT

Ref legal event code: MK05

Ref document number: 805930

Country of ref document: AT

Kind code of ref document: T

Effective date: 20160608

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: HR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20160608

Ref country code: SE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20160608

Ref country code: ES

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20160608

Ref country code: LV

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20160608

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20160909

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: EE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20160608

Ref country code: IS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20161008

Ref country code: CZ

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20160608

Ref country code: SK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20160608

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20160608

Ref country code: RO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20160608

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: PL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20160608

Ref country code: AT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20160608

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20160608

Ref country code: PT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20161010

REG Reference to a national code

Ref country code: DE

Ref legal event code: R097

Ref document number: 602008044641

Country of ref document: DE

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MC

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20160608

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

26N No opposition filed

Effective date: 20170309

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20160608

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20160608

REG Reference to a national code

Ref country code: IE

Ref legal event code: MM4A

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20160926

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20160930

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20160930

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20160926

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 10

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: CY

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20160608

Ref country code: HU

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT; INVALID AB INITIO

Effective date: 20080926

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: TR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20160608

Ref country code: MT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20160930

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BG

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20160608

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 11

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20180920

Year of fee payment: 11

Ref country code: FR

Payment date: 20180925

Year of fee payment: 11

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 20180924

Year of fee payment: 11

Ref country code: GB

Payment date: 20180919

Year of fee payment: 11

REG Reference to a national code

Ref country code: DE

Ref legal event code: R119

Ref document number: 602008044641

Country of ref document: DE

REG Reference to a national code

Ref country code: NL

Ref legal event code: MM

Effective date: 20191001

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20200401

Ref country code: NL

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20191001

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20190926

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20190930

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20190926